An excerpt from Deitsch's report; it mentions that Eminem's interview with Musberger was five months in the making:

Bonnell said what viewers did not immediately recognize was that Eminem took on the persona of his Berzerk character in the video. "He was just messing with everyone," Bonnell said. "We had no idea he would do that, but if you see the music video, it's him looking into the camera and doing a throwback to the '80s. You clearly saw after the video was over, he became Marshall Mathers again. He was goofing around."